# -*- coding:utf-8 -*-
import urllib2
import cookielib

# urllib2下载网页的三种方法

url = 'http://www.baidu.com'

print '第一种方法'

response1 = urllib2.urlopen(url)
print response1.getcode()
print len(response1.read())


print '第二种方法'
request = urllib2.Request(url)
request.add_header('user-agent', 'Mozilla/5.0')
response2 = urllib2.urlopen(request)
print response2.getcode()
print len(response2.read())


print '第三种方法'
cj = cookielib.CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
urllib2.install_opener(opener)
response3 = urllib2.urlopen(url)
print response3.getcode()
print cj
print response3.read()

# 网页解析器：从网页中提取有价值数据的工具
# 几种网页解析器：正则表达式 / html.parser / Beautiful Soup / lxml
# 结构化解析-DOM
